Field study Field study 4 commercial organic herds Jan 2012 to - PDF document

Different production environments - the same genetic material Effect of sire on pig leg health in commercial organic herds Photo: Jenny Svennás-Gillner, SLU Photo: Anna Wallenbeck Photo: Haoyu Liu Photo: Eva Persson Photo: Maria Alarik Anna Wallenbeck 1 , Christina Eliasson 1 and Maria Alarik 2 Conventional Organic 1 Swedish University of Agricultural Sciences , Department of Animal Breeding and Genetics 2 Swedish Rural Economy and Agricultural Societies How does ’conventional’ breeds suit organic production environments? Anna.Wallenbeck@slu.se Breeding strategy – how to use the available breeds in the best way. Funded by SLU EkoForsk The proportion of organic pigs with leg joint remarks (arthritis) at Aims slaughter is high Assess differences between available sire breeds (Hampshire and Duroc) and between individual sires within breed: • Clinical locomotion, lameness and swollen joints among organically raised offspring • Leg joint remarks at slaughter among organically raised offspring Heldmer, 2012 Photo: Christina Eliasson Photo: Christina Eliasson Field study Field study 4 commercial organic herds Jan 2012 to March 2013 Insemination Farrowing Weaning Slaughter AI-Hampshire boars AI-Duroc boars Electronic ear tags 90 days 170 days Every second sow Every second sow inseminated with H inseminated with D Locomotion and exterior examination Slaughter remarks Aim: 1000 slaughtered pigs with known sire (500 per breed) Photos: Linda Engblom and Christina Eliasson

Locomotion and exterior examination Statistical analyses • Back 99 litters (and Yorkshire x Landrace sows), ws), • Leg conformation 1115 pigs at slaughter • Movement • Lameness Breed differences : SAS GLM (cont. scale) le) • Swollen leg joints y = breed + gender + herd + e Variation among sires within breed: SAS S • 909 pigs at examination 1 GLIMMIXED (binomial scale) (90 (±19.5) days of age) y = sire random + gender + herd + e • 1012 pigs at examination 2 (170 (±17.4) days of age) Protocol modified from Quality Genetics protocol Results - Movement Results - Movement 100 • No significant differences between sire breeds 90 80 • Sign effect of individual sire at first (p=0.036) and 70 Percent of pigs second (p=0.087) examination 60 90 days 50 170 days • Hampshire: Individual sire accounted for 12 to 15 % of the 40 variation, corresponding to a moderate to high heritability 30 20 • Duroc: Individual sire accounted for 0 to 0.2 % of the 10 variation 0 1 = Serpentine movements 2 3 = Normal 4 5 = Stiff movements • Insufficient data for genetic analyses The proportion of pigs with mild movement disorders increases with age. The proportion of pigs with severe disorders was low. Photo: Anna Wallenbeck Results - Lameness Results - Swollen leg joints 100 120 90 80 100 70 Percent of pigs Percent of pigs 80 60 90 days 90 days 50 60 170 days 170 days 40 40 30 20 20 10 0 0 0 = Not lame 1 = Visual lameness, using 2 = Nod with the head, 3 = Not using the affected No Yes all 4 legs unburden the affected leg leg The proportion of pigs with lameness increases with age. The proportion of pigs with swollen leg joints increases with age. No difference between sire breeds. No difference between sire breeds.

Leg joint remarks at slaughter Conclusions • Low prevalence! • No evidence that leg health can be improved in • Just below 2 % of the pigs in the study had leg joint Swedish commercial organic herds by choice of sire remarks at slaughter, in line with conventionally raised breed (Hampshire/Duroc) pigs. • Leg health may be improved by choosing the best individual sires, irrespective of breed Thank you for your attention! Could indicate no/weak relationships between clinical leg health and leg joint remarks at slaughter Anna.Wallenbeck@slu.se Photo: Anna Wallenbeck